1. Field of the Invention
The present invention relates to an improved exhaust system for a motorcycle having an engine, an exhaust pipe that is connected to the engine, and a muffler that is connected to the exhaust pipe.
2. Description of Related Art
Conventional motorcycle exhaust systems have an exhaust pipe connected to an engine and a muffler connected to the exhaust pipe. Some types of mufflers have a casing that surrounds a tail pipe that forms a rear section of the exhaust pipe. In addition, sound absorbing material is filled between the casing and the tail pipe.
In order to improve the sound absorbing effect of the muffler, the tail pipe may be lengthened as much as possible. The tail pipe disposed inside the casing has a main pipe and a pair of branch pipes that branch from and are contiguous with the main pipe (for example, refer to JP-UM-A-5-75422).
It is conceivable that an even better sound absorbing effect could be achieved in the muffler by filling sound absorbing material between the casing and the pair of branch pipes that branch from the main pipe and extends to the rear. However, the volume of the space formed between the casing and the branch pipes may be smaller than the volume of the space formed in the main pipe section, and thus the amount of sound absorbing material that can be filled is limited. As a result, there is a problem that the sound absorbing effect generated by the sound absorbing material is inadequate.